The objectives of our program of research are to study the different phases of circulatory dynamics and their control. Both normal and abnormal control systems are being studied since many diseases such as hypertension, shock, edema, neurogenic and endocrine disorders, and renal diseases are manifestations of abnormal circulatory control. Our efforts continue to be directed toward the development of an overall quantitative mathematical analysis of the body's circulatory system, which is in accord with both normal physiology and pathological states. The mathematical model requires a quantitative description of the different systems and subsystems involved in circulatory control as well as the interrelationships between them. Data for the mathematic analysis is continually being updated with experimental data from our laboratory. Research is being conducted in two phases. First, the different laboratories within the Program Project are making appropriate measurements of various quantitative relationships within the circulatory system. Second, the data provided from experimentation on dogs, rats, hamsters and chick embryos are used to expand and redefine our mathematical analysis--particularly, the current version of the large model of the overall control of the circulation. In turn, the mathematical analyses provide the basis for much of the new animal experimentation.